Nikki Haley burst onto the national political stage four months ago as one of Sarah Palin's "mama grizzlies" and has appeared poised to make history as South Carolina's first woman and Indian-American governor.
But now some polls show the race tightening to single digits amid new accusations that Haley has failed to be as transparent as promised -- developments which draw into question whether the Republican state representative can seal the deal.
A collection of emails obtained by the Associated Press Saturday show that Haley was effectively forced out of her most recent job as a hospital fundraiser despite her public statements that she left amicably and voluntarily.
And Haley continues to be trailed by questions about her experience as a "business person" who has not owned a business, her legislative achievements in the state general assembly and two separate, unsubstantiated claims of extramarital affairs.
"The momentum is in our court," said an aide to Democrat Vincent Sheheen. "Voters have a very distinct choice in terms of trust and integrity."
Sheheen's latest ad hammers Haley for late and unpaid taxes and ties her to the scandal-tainted outgoing Republican Gov. Mark Sanford. "Can we afford another governor who says one thing and does another?" the narrator asks, as Sanford's face appears next to Haley.
Sanford, who is term-limited, was caught in an affair with an Argentine mistress last year despite repeated public denials.
Vince Sheheen "has spent all of his time, and hundreds of thousands of dollars, slinging mud at Nikki Haley in a desperate attempt to distract voters from his liberal record and embrace of the Obama agenda. It's not working," said Haley campaign spokesman Rob Godfrey.
In Haley's latest ad, Sheheen is cast as a "liberal, Columbia insider, and a trial lawyer" who would be bad for South Carolina businesses.
"Taxpayers and small businesses are already squeezed, and now they're on the hook for billions of dollars thanks to President Obama's spending and health care disasters," Haley said at a rally Thursday. "The last thing we can afford is a governor who supports ObamaCare like Vince Sheheen."
Haley, Sheheen Spar Over Business Vote
Haley has called for elimination of the state's corporate income tax while Sheheen has not.
But South Carolina political experts say it's Haley's tenuous support among the business community that could be her weakness.
"The Chamber of Commerce folks, mainstream business community and moderate Republican leaders in the general assembly haven't been moving to her," said University of South Carolina political scientist Mark Tompkins. "These folks haven't been enthusiastic, so the question is will they stay home."
Meanwhile, Sheheen – a conservative Democrat – has convinced some members of the business community and Republicans to be "relatively content" with him, Tompkins said.
Haley, a three-term state representative, does continue to have the enthusiastic support of the state's conservative base, which helped propel her to victory in the primary over three early front-runners.
And she has the valuable endorsements of tea party groups, South Carolina's former first lady Jenny Sanford, and former Alaska Gov. Sarah Palin. It's unclear whether Palin, who is credited with helping to elevate Haley's campaign, will return to the state to help in the final stretch.
Veteran Republican operative Trey Walker, who helped orchestrate John McCain's 2008 primary win in South Carlina, recently joined the Haley team to help with communications strategy.
"Even polls done by Democrats, for Democrats, show Nikki in the lead," said Godfrey. "We're very comfortable with where the race is."
Both camps say the final three weeks will be an intense battle for independent and undecided voters -- and getting them to turn out.
"It's still an uphill battle for Vince Sheheen in a Republican dominated state in a Republican dominated election," said Winthrop University political scientist Scott Huffmon. "Sheheen really has to continue to make people uncomfortable with Nikki Haley but that negative campaigning can depress turnout which would hurt him too."
The candidates have three more debates before election day, Oct. 19, 25 and 26.